Using SharePoint 2013 Federated Search with an OpenSearch connection, and the response has multiple extention fields (which are processed by custom Search Display Template. Unfortunately, depending upon data returned, receive an error of "Microsoft.Office.Server.Search.Query.Pipeline.Connectors.OpenSearchReaderConnector : Response length exceeded maximum length" which appears to be only 64k (while the response returned is 124177 bytes).
Entry from log file:
09/02/2015 12:21:54.06
NodeRunnerQuery1-3b80be33-d85d- (0x43BC)
0x4228
Search
Query Processing
aizfj
Unexpected
Microsoft.Office.Server.Search.Query.Pipeline.Connectors.OpenSearchReaderConnector : Response length exceeded maximum length: [url=https://spus001sha50.russellreynolds.com:9090/api/opensearch/rrakman?searchterms=boston&startindex=0&count=10],
[MaximumResponseLength=64] System.Net.WebException: Response length exceeded maximum length: [url=https://spus001sha50.russellreynolds.com:9090/api/opensearch/rrakman?searchterms=boston&startindex=0&count=10], [MaximumResponseLength=64], [ReceivedResponseLength=124177
bytes] at Microsoft.Office.Server.Search.Query.Pipeline.Connectors.OpenSearchReaderConnector.GetXmlFromUrl(String url)
a2102a9d-50a6-7094-e886-e908470b912d